This invention relates to an osteoinductive and osteoconductive composition containing demineralized fibrous bone elements in combination-with non-fibrous bone elements that are demineralized, partially demineralized or non-demineralized. More particularly, the invention relates to demineralized fibrous bone elements having a relatively high median length to median thickness ratio and relatively high surface area to volume ratio; demineralized, partially demineralized or non-demineralized non-fibrous bone elements that vary from “mostly irregular” to “mostly regular” in shape and not more than 10 mm in any measurable component of the shape to determine size, e.g., height, base, length, width, diameter or radius; and to a volume maintaining osteoinductive/osteoconductive composition containing such fibrous and non-fibrous elements within a biocompatible fluid carrier.
The use of pulverized exogenous bone growth material, e.g., derived from demineralized allogenic or xenogenic bone in the surgical repair or reconstruction of defective or diseased bone is known. See, in this regard, the disclosures of U.S. Pat. Nos. 4,394,370, 4,440,750, 4,472,840, 4,485,097, 4,678,470, and 4,743,259; Bolander et al., “The Use of Demineralized Bone Matrix in the Repair of Segmental Defects”, The Journal of Bone and Joint Surgery, Vol. 68-A, No. 8, pp. 1264-1273; Glowackie et al, “Demineralized Bone Implants”, Symposium on Horizons in Plastic Surgery, Vol. 12, No. 2; pp. 233-241 (1985); Gepstein et al., “Bridging Large Defects in Bone by Demineralized Bone Matrix in the Form of a Powder”, The Journal of Bone and Joint Surgery, Vol. 69-A, No. 7, pp. 984-991 (1987); Mellonig, “Decalcified Freeze-Dried Bone Allograft as an Implant Material In Human Periodontal Defects”, The International Journal of Periodontics and Restorative Dentistry, pp. 41-45 (June, 1984); Kaban et al., “Treatment of Jaw Defects with Demineralized Bone Implants”, Journal of Oral and Maxillofacial Surgery, pp. 623-626 (Jun. 6, 1989); and, Todescan et al., “A Small Animal Model for Investigating Endosseous Dental Implants: Effect of Graft Materials on Healing of Endosseous, Porous-Surfaced Implants Placed in a Fresh Extraction Socket”, The International Journal of Oral & Maxillofacial Implants Vol. 2, No. 4, pp. 217-223 (1987). According to Kakincki et al., “Human bone matrix gelatin as a clinical alloimplant”, International Orthopaedics, 9, pp. 181-188 (1985), a water insoluble osteoinductive/osteoconductive substance referred to therein as “bone matrix gelatin” which was obtained by decalcifying (ire., demineralizing) bone was successfully employed as an alloimplant for the treatment of bone defects and other disorders. An apparently similar water insoluble osteoinductive/osteoconductive material, referred to as “decalcified bone matrix”, is disclosed in McLaughlin et al., “Enhancement of Bone Ingrowth by the Use of Bone Matrix as a Biologic Cement”, Clinical Orthopaedics and Related Research, No. 183, pp. 255-261 (March, 1984). However, the prior art demineralized bone products have proven to be unsatisfactory for applications requiring a bone product, which maintains the volume of bone defect sites and allows for firm packing. Thus, an osteoinductive/osteoconductive composition, which maintains its cohesiveness and volume and resists erosion, would be highly desirable.